430 



ME. S. S. BrCKMAX OX 



[vol. Ixxml^ 



Mr. Eicharclson says with regard to the Burton "White Bed : 

 ' the very white aspect o£ the stone was due to weathering of the 

 surface.' ^ This is not my experience — the true lithographic 

 stone is beautifully white, inside as well as outside. 



The Black Bocks which lie out to sea immediateh'' west of the 

 first fault from West Ba}^, should repay investigation. Hitherto 

 they seem to have been neglected ; but this may be due to the 

 fact that thej^ are inaccessible, except during certain low tides. 

 It was only dviring my last visit to Ej'pe (1920) that I found 

 them sufficiently uncovered for a short examination, which en- 

 abled me to collect certain specimens, indicative of the Astarte- 

 Bed {^Garaniicnui) of Burton Bradstock, from some masses well 



Diagram 12. — One of ilie Blaclc liocJiS (Dorset). 



A = Ironshot fossiliferoiis (Garantiana) rock. 

 B = Very hard, fine-grained grey rock (White Bed equivalent). 

 C = Ironshot, like the hard portion of the Vetney Cross Astaiie Bed 

 (Garcnitiana). 



off shore, but iust landward of the bis: rock. At mv next visit at 

 low tide these rocks were not accessible ; but, nearer the beach 

 and among the shingle of the beach, were found certain blocks 

 which could be recognized as scission bed. Bed Bed, scliJcenhacln 

 and zigzag beds, besides the mass of Astarte Bed just mentioned. 

 At certain states of the shingle these beds are buried ; but, given^ 

 favourable conditions of tide and shingle, the Black Rocks should_ 

 yield a good harvest. However, heav}'' tools are a necessit}^ 



To return for a moment to the niortense bed : there is reason 

 to suppose that this bed was originally of Avide geographical 

 extent — possibly from the Hebrides to Italy and the Carpathians, 

 certainly from Sherborne (Dorset) through France to Wlirtemberg.. 

 But, although it was originallj^ deposited over so vast an area, the 

 bed is now preserved only at a few widely-distant localities and is. 

 lacking from intermediate areas — much of it was wholly destroyed. 



1 IX, 2, p. 56. 



